The use of product cushioning devices for shock sensitive products has been known for many years. Typically, cushioning for shock sensitive devices comprises a number of different approaches, each of which may have its own particular advantages and/or disadvantages.
For example, it has been known for many years to wrap shock sensitive or delicate devices or merchandise in tissue paper, and to cushion the products with loosely balled tissue paper. Another use of paper has been shredded paper, or excelsior. A more elegant approach has been to use bubble-pack, which comprises a sheet material having a plurality of contained bubbles of air formed therein. Another approach which has been used for many years has been the use of a plurality of discrete molded foamed polystyrene pellets, sometimes referred to as "peanuts" in the industry, to fill around a product in a container.
As the requirement for better packaging and cushioning became more demanding, for example with the introduction to the market of complicated and expensive electronics devices such as computer monitors, and more particularly notebook computers, printed circuit boards, and the like, the requirement arose for more sophisticated and better shock absorbing cushioning devices. Standards were developed for acceptance of cushioning devices, including drop tests and the like, to determine if such devices would protect the shock sensitive product from shock acceleration greater than the product's fragility level--typically, from 20 g's to 100 g's.
This has given rise to the use of such products as honeycomb cardboard, and particularly foamed polystyrene, foamed polyurethane, foamed polypropylene, or foamed polyethylene. Flexible foam devices are well known for use as corner pieces or edge pieces. Likewise, foamed polystyrene products--which are more rigid--are also well known for use as corner pieces or end caps; and very often, they are product specific in that they are particularly molded having a specific configuration for use with a particular product.
In general, however, flexible foam cushioning devices, and foamed polystyrene cushioning devices, are not recyclable. There are several reasons for that condition: The first is that flexible foam cushioning devices, and polystyrene cushioning devices, tend to be quite bulky, and are usually discarded with the packaging container in which the product has been shipped. There are very few specific recycling depots that are set up for either flexible foam or especially polystyrene cushioning devices; and, in any event, foamed polystyrene and foamed polyurethane cannot generally be recycled. Its re-usability may be provided for, particularly as general corner pieces, if they remain intact, or as product specific end caps; but, unless such foamed polystyrene cushioning devices are being used in a closed shipping system, they will not be recovered for re-use. Moreover, foamed polystyrene cushioning devices tend to be very frangible, and do not maintain their integrity very well once they have been used and removed from the packaging container in which they are shipped.
More elegant cushioning devices have more recently entered the market, comprising different types of blow-molded or other plastics shell products, most of which are closed structures which are filled with air or other gas. Some such structures are inflatable, some are closed, and some may be open to the atmosphere but are formed of a relatively rigid material. All such products are generally formed from high density polyethylene, which may be recycled because it is easily chopped up and made into further products, or such products may be re-usable if they are employed in a closed delivery and recovery system. Low density polyethylene may also be found in products such as those described immediately above, although its use is quite limited at the present time.
As will be discussed in greater detail hereafter, the present invention also provides a recyclable and re-usable product cushioning device which has a unitary construction and is formed of a plastics material. As noted, the present invention provides such a product cushioning device as a corner piece, an end piece, or an end cap. However, the present invention does not present a closed structure, such as a number of prior art devices which are discussed hereafter; rather, the present invention provides a product cushioning device which is such that it may be stackable. This feature means that product cushioning devices in keeping with the present invention may be stored in much smaller storage volumes than previously may have been required at the factory or shipping warehouse where the products in association with which the product cushioning devices of the present invention will be used. Moreover, when the products have been delivered to the end user, the product cushioning devices may again be stacked for re-usability, or even roughly cut or chopped up for recycling of the material.
Still further, as will be described in greater detail hereafter, the present invention provides unitary product cushioning devices which afford at least two discrete contact and shock transmitting regions in at least one direction; end caps and corner pieces in keeping with the present invention provide at least two directions of shock absorbing protection.